The insulin-sensitizing activity of moderate alcohol consumption may promote leanness in women.

Cross-sectional epidemiology reveals that women who drink alcohol regularly and moderately, on average, tend to have a decidedly lower body-mass index (BMI) than non-drinking women, despite slightly higher caloric intakes. In men, moderate drinkers are no heavier than non-drinkers, yet they consume considerably more calories. The thermogenic effect which this implies is not explained by the modest acute thermic effect of ethanol ingestion. However, there is indirect evidence that regular alcohol consumption has an insulin-sensitizing effect on skeletal muscle that down-regulates insulin secretion. Decreased insulin activity on adipocytes and the liver may discourage fat storage and promote hepatic mechanisms of ketogenesis, gluconeogenesis, and associated thermogenesis, thus possibly accounting for the relative leanness of female drinkers. The possibility that prescribing moderate alcohol intake could aid weight control in non-drinking overweight females should receive clinical evaluation. The impact of moderate drinking on risk for diabetes in women appears to be quite dramatic. Copyright 2000 Harcourt Publishers. Ltd.